The Peak Downs Shire hosts significant coal deposits. Mining began in the late 1970's with the opening of Gregory coal mine (1979). This was followed by the Oaky Creek coal mine in 1983. The township of Tieri was constructed to house the operational workforce for the latter mine. Underground mining operations commenced at German Creek Southern in December 1989 and three more mines were commissioned in the 1990's at Ensham, Crinum and Kestrel.

Peak Downs Shire is host to about 10% of the identified resources of Permian-age Bowen Basin coal in Queensland. Coal resources are located in within three coal-bearing sequences that lie in an acuate zone within the eastern portion of the shire. In this acuate zone, there are six operating coal mines (mentioned above) and two undeveloped coal resources (Valeria and Liskeard). Ongoing exploration continues to identify and upgrade the status of coal resources.

The Key Coal Resources of the Peak Downs Shire, prior to the 2008 Shire Amalgamations.

Valeria
The Valeria coal deposit is centred about 20 km southwest of Capella. Valeria contains an estimated 200 Mt of Measured and 240 Mt of Indicated potential open cut thermal coal (Rio Tinto 2007). Coal occurs in several seams within the Early Permian Aldebaran Sandstone and Reids Dome beds that dip between 5-15 degrees to the east. Mining of this deposit has not commenced.

German Creek (South)
The German Creek South coal mine is located about 20 km east of Tieri, or 64km east of Capella. In January 2004, a Measured and Indicated Resource containing 248 Mt of coking coal was estimated for the German Creek mine. Up to five minable coal seams are present within the east dipping German Creek Formation, most valuable being the German Creek Seam.

German Creek mining operations are managed by Capricorn Coal Management Ltd (a wholly owned subsidiary of Anglo Coal Australia Ltd). Underground operations at Southern Colliery ceased in June 2006 after producing 36 Mt of saleable coal since 1988.

Grasstree Colliery longwall operations commenced in September 2006 to extract coal resources down dip of Southern Colliery. When Grasstree is fully operational it is expected to produce 4.5 Mt of hard coking coal annually. Saleable coal production from underground mining at German Creek was 2.8 Mt in 2006/07 (DME 2007). Contract thin-seam mining of the Aquila Seam using the board and pillar method is in progress above the Southern Colliery.

Oaky Creek
The Oaky Creek coal mine is located 17 kilometres east-southeast of Tieri. Measured and Indicated coking coal resources totalling 345 Mt have been estimated (Xstrata 2007). Additional Inferred coking coal resources of 130 Mt also exist. Up to seven coal seams are present but only the Aquila, Pleiades and German Creek seams are included the resource estimates. The host unit (German Creek Formation) dips easterly at 5-10 degrees.

The Oaky Creek operation includes two underground mines (Oaky Creek No.1 and Oaky North). Longwall retreat extraction methods are utilised; open mining ceased in December 2006. Saleable coking coal production for 2006/07 was 7.1 Mt (DME 2007). Oaky Creek will have the capacity to produce up to 8.7 Mtpa when the second longwall unit at Oaky Creek No1 becomes fully operational.

Liskeard
The Liskeard coal deposit is located 9 km south of Tieri. A Measured Resource of 5.6 Mt of potentially open cut coking coal has been estimated (BHPB 2007). Most of the resource is within the flat-lying, 1.5m thick Liskeard Seam, near the top of the Freitag Formation.

The deposit represents an extension of coal resources in the Gregory-Crinum mine area.

Gregory-Crinum
The Gregory-Crinum coal mine is located 34km east of Capella. Measured coking and thermal coal resources of 134 Mt suitable for underground mining has been estimated (BHPB 2007). There are Measured and Indicated coking and thermal coal resources of 9.7 Mt suitable for open cut mining. Coal resources are largely within the 3.5 m thick Lilyvale Seam of the German Creek Formation.

The Gregory-Crinum operation includes two underground mines (Crinum and Crinum East) and one open-cut mine (Gregory). The underground mines use longwall retreat extraction methods, while the open cut uses draglines for overburden removal. Saleable coking and thermal coal production in 2006/07 was 4.7 Mt (DME 2007).

Kestrel
The Kestrel coal mine is located 39km east of Capella and contains Proved and Probable Reserves of 140 Mt of coking and thermal coal suitable for underground mining. An additional 165 Mt of Indicated thermal coal resource has been estimated for Kestrel West (Rio Tinto 2007) The 3 m thick, German Creek Seam within the German Creek Formation is the only economic seam.

The Kestrel operation involves underground mining using two longwall units. Kestrel produced 2.6 Mt of saleable coking coal and 1.1 Mt of saleable thermal coal in 2006/07 (DME 2007).

Ensham
The Ensham coal mine is located about 60 km kilometres southeast of Capella. A Measured Resource of 103 Mt and Indicated Resource of 55 Mt of potentially open-cut thermal resources have been estimated (JB Mining Services 2005). A further 170 Mt of Indicated and 459 Mt of Inferred underground thermal and coking coal resources exist. Coal resources are mainly in the Aries and Castor Seams within the Rangal Coal Measures. At North Ensham, the Pollux Seam is mined from the Yongala pit and coalesces with the Castor Seam. Coal seams currently mined dip about five degrees to the west.

The Ensham operation involves open-cut mining from five large pits utilising three draglines. About 7.5 Mt of saleable thermal coal was produced in 2006/07 and the mine has a current production capacity of up to 12 Mtpa. A fourth dragline (Bucyrus 8750-63) was commissioned in February 2007.

Ensham Resources Ltd aims to more than double annual production to 20 Mt with continued expansions of the open-pit operations and the planned development of a longwall underground operation by 2009.

Information courtesy Phil Ferenczi, Regional Geologist, DME Central Region, Rockhampton. 2007